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REV it UP – electric cars

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REV it UP is a Taranaki-based Participatory Science Platform (PSP) project supported by the New Zealand Government. New Plymouth Boys’ High School and local engineering firm Falcon Engineering, with the support of Taranaki Venture Trust, are working together to research, design and build an electric vehicle (EV) and test it against its petrol-powered equivalent.

The first phase is research. Students have been investigating the various inputs and design requirements needed for an electric engine that will be used in an existing car body, a Toyota MR2. The students are also rebuilding a second, petrol-powered vehicle. Building the two vehicles will provide data to enable specific comparisons such as energy used per kilometre, cost per kilometre and theoretical range and performance characteristics of each vehicle.

The students will then be able to show which system is the most cost-efficient to run when comparing the cost of fuel and electricity energy equivalents per unit cost versus power output and cost per kilometre.

Electric vehicles are not all the same

There are two main types of EV. Battery electric vehicles (BEVs) are fuelled only by the battery, which is charged by plugging in to an electric power point. Plug-in hybrid electric vehicles (PHEVs) have two engines – one fuelled by a battery, which is charged by plugging in to an electric power point, and the other fuelled by petrol or diesel.

Hybrid vehicles that you do not plug in are not technically classified as electric vehicles. Their batteries are charged by recapturing energy from electricity generated by the engine or when braking. They are more energy efficient than a traditional petrol or diesel vehicle and do produce less emissions.

Increasing popularity of electric vehicles

In May 2016, the New Zealand Government set a target to double EV registrations each year, aiming for 64,000 by 2021. At the time of the announcement, there were 2,000 electric vehicles registered. Significant improvements to battery technology and a desire for reduced emissions are making EVs more attractive to the public.

It’s clear that support for EVs is gathering momentum with registrations already double what they were last year. It’s fantastic to see people and businesses recognise the environmental and economic benefits of going electric

Transport Minister, Honourable Simon Bridges, May 2016

Electric cars were first developed in the 1800s, and the first hybrid concept car was seen at the Tokyo Motor Show in 1995. For more on the development of electric vehicles, see the Electric car history timeline below.

I’ve actually made a prediction that within 30 years a majority of new cars made in the United States will be electric. And I don’t mean hybrid, I mean fully electric.

What is the science?

All vehicles use energy conversion technology to turn potential (stored) energy into kinetic (moving) energy. In a car fuelled by fossil fuels, such as petrol or diesel, the energy is stored in a chemical form. The energy transformation inside a combustion engine is a chemical reaction in which the burning of hydrocarbon molecules in fossil fuels pushes the pistons, turning a drive shaft, which turns the wheels.

Electric cars also use stored chemical energy, held in batteries, which is released in electrochemical reactions. The energy produced by the car’s batteries runs a controller, which runs an electric motor that turns the wheels of the car.

How do electric motors work?

Electric motors work by using electricity, magnetism and movement. DC (direct current) electric motors use a system of magnets and coils to turn the drive shaft.

The most common motor used by home built EVs is the DC series wound electric motor. They run quietly and produce enough torque for modern driving. They have a direct drive – so no gears or transmission. Commercial, mass produced EVs use AC motors because of the simple regeneration they allow.

The Tesla Model S uses a 3-phase, 4-pole AC electric motor and is the best-performing electric car to date, outperforming all similar internal combustion engines.

REV it UP – a community initiative

REV it UP has its own workshop space in New Plymouth, creating a space outside of school hours where the students can learn and work together in an atmosphere that is more like a workshop than school. A local business, Falcon Engineering, is one of the driving forces behind the project.

We need good apprentices and engineers, this is one way we can upskill and encourage local young people into the industry

Local engineer

Engineers from Falcon, the hard materials technology teacher from New Plymouth Boys’ High School, Steve Leppard, as well as other community members spend time with the boys, teaching, supervising and motivating them to give things a go.

Everyone is encouraged to work to their strengths, and the participating students are learning basic engineering skills, including welding, electronics and CAD drawing. In order for the project to progress, they have to collaborate. Everyone has responsibilities, and they take pride in their space. There is a strong sense of project ownership, made possible by an inspiring school-community collaboration.